128321568 has 72 divisors (see below), whose sum is σ = 366912000. Its totient is φ = 42539904.

The previous prime is 128321551. The next prime is 128321597. The reversal of 128321568 is 865123821.

It is a happy number.

128321568 is a `hidden beast` number, since 12 + 83 + 2 + 1 + 568 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56193 + ... + 58431.

It is an arithmetic number, because the mean of its divisors is an integer number (5096000).

Almost surely, 2^128321568 is an apocalyptic number.

128321568 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128321568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (183456000).

128321568 is an abundant number, since it is smaller than the sum of its proper divisors (238590432).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128321568 is a wasteful number, since it uses less digits than its factorization.

128321568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2454 (or 2443 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 128321568 is about 11327.9110165997. The cubic root of 128321568 is about 504.3900985885.

It can be divided in two parts, 12832 and 1568, that added together give a square (14400 = 120²).

The spelling of 128321568 in words is "one hundred twenty-eight million, three hundred twenty-one thousand, five hundred sixty-eight".